Category
AI email assistants: what they are and who makes them
ai-first email clients, background inbox agents, add-ins for outlook and gmail, shared-inbox tools with ai: Shortwave, Fyxer, Spark Mail through Canary Mail.
Types of AI email assistants
AI-first email clients
Shortwave, Superhuman Mail and Zero replace your mail app with one built around AI search and drafting. They offer the deepest features of the group, and they ask the biggest change in daily habit, since shortcuts, layout and search all differ from the client you leave behind.
Background inbox agents
Fyxer works without a new interface: it labels mail, drafts replies in your inbox and writes meeting follow-ups. You review its work rather than operate it, which suits people with little time for email and a mailbox that stays at Gmail or Microsoft.
Add-ins for Outlook and Gmail
MailMaestro, Mailbutler, Mailmeteor and Gemini in Gmail sit inside the mail window you already use. Setup takes minutes and nothing is migrated, but the feature set stays narrower than in a full client, and some of these tools are stronger at writing than at sorting.
Shared-inbox tools with AI
Missive combines assignment, internal threads and an AI assistant for several people working the same mailbox, with rules and automations on its higher tiers. Spark Mail offers a lighter version of that idea through its separate team plans for people who share work but not a full inbox.
Facts at a glance
| Tool | Publisher | Based in | Access |
|---|---|---|---|
| Shortwave | Shortwave Communications, Inc. | United States | Trial |
| Fyxer | Fyxer AI Limited | United Kingdom | Trial + API |
| Spark Mail | Spark Mail Limited | Ireland | Free tier |
| Mailbutler | Mailbutler GmbH | Germany | Trial |
| Missive | Heliom Inc. | Canada | Trial + API |
| MailMaestro | Maestro Labs Pte. Ltd. | Singapore | Trial |
| Superhuman Mail | Superhuman Platform Inc. (formerly Grammarly) | United States | Paid |
| Mailmeteor | Mailmeteor SAS | France | Free tier |
| Zero | Mail-0 open-source project | Not stated in the project's repository | Paid |
| Gemini in Gmail | United States | Paid | |
| Canary Mail | Canary Mail | United States | Free tier |
